$2 Cu_2O_{(s)} + Cu_2S_{(s)} \longrightarrow 6 Cu_{(s)} + SO_{2(g)}$
In the above reaction,the oxidant and reductant respectively are:

Which of the following reactions represents a redox reaction involving water?

$10 \, \text{mole}$ of ferric oxalate is oxidised by $x \, \text{mole}$ of $MnO_4^-$ in acidic medium. The value of $x$ is

$500$ mL of $0.2$ $M$ $MnO_4^-$ solution in basic medium when mixed with $500$ mL of $1.5$ $M$ $KI$ solution, oxidises iodide ions to liberate molecular iodine. This liberated iodine is then titrated with a standard $x$ $M$ thiosulphate solution in presence of starch. If $300$ mL of thiosulphate was consumed, then the value of $x$ is . . . . . . .

Match each of the reactions given in Column $I$ with the corresponding product$(s)$ given in Column $II$.

Column $I$	Column $II$
$(A)$ $Cu + \text{dil } HNO_3$	$(p)$ $NO$
$(B)$ $Cu + \text{conc } HNO_3$	$(q)$ $NO_2$
$(C)$ $Zn + \text{dil } HNO_3$	$(r)$ $N_2O$
$(D)$ $Zn + \text{conc } HNO_3$	$(s)$ $Cu(NO_3)_2$
	$(t)$ $Zn(NO_3)_2$

How much volume of $5 \ M$ $HNO_3$ is required to oxidize $16 \ g$ of $Fe^{+2}$ if $HNO_3$ is converted into $NO$? (Answer in $mL$)